(a) Field of the Invention
The present disclosure relates to a method of preparing trichlorosilane, and more particularly, to a method of preparing trichlorosilane which trichlorosilane can be obtained with an improved yield using a catalyst-supported silicon.
(b) Description of the Related Art
Trichlorosilane (TCS) is one of the main materials for preparing silicon for use in a semiconductor or a solar cell. For a method for preparation of trichlorosilane, direct chlorination and hydrochlorination (HC) are commercially utilized. Hydrochlorination is performed by supplying silicon tetrachloride (STC) and hydrogen (H2) to metallurgical silicon (MG-Si) under conditions of a temperature of 500 to 600° C. and a pressure of 20 to 30 bar.
Various methods have been proposed to increase the reaction rate of hydrochlorination. Japanese Patent Laid-Open NOs. Showa56-73617 and Showa60-36318 disclose a method of adding a copper (Cu) catalyst, and Japanese Patent Laid-Open No. Showa63-100015 discloses a method of adding a Cu mixture to the reaction.
However, a copper catalyst contributes to an increase in the yield of trichlorosilane in a fixed bed reactor, but exhibits low contribution to a commercial process because copper particles may aggregate due to the small particle size thereof and collision of metallurgical silicon particles causes a loss of the catalyst on the surface thereof in a fluidized bed reactor.
In order to solve these problems, although a variety of attempts have been made to support a copper catalyst on the surface of metallurgical silicon as in Japanese Patent No. 3708649 and Korean Patent Application No. 2007-7023115, they are problematic in that the preparation process is complicated and the reaction time increases to deteriorate the catalytic activity.